I. Technical Field
Embodiments described herein relate to protection of loudspeakers during operation.
II. Background Art
Devices, such as personal computers and laptops, cellular and smart phones, wireless device accessories, headsets, personal digital assistants (PDAs), portable music players, handheld gaming devices, home electronics and entertainment devices, televisions, stand-alone loudspeaker units, etc., include loudspeakers, such as microspeakers, for reproduction or playback of an audio signal. Loudspeakers may suffer damage and/or failures from extended high-stress use and over-excursion scenarios. For example, extended use at high audio volume levels and/or in high temperatures can cause breakdowns by melting the adhesives used to attach the voice coils in loudspeakers. High audio volume levels can also cause diaphragms of speakers to travel (i.e., undergo an excursion) beyond their mechanical capabilities resulting in permanent damage to the suspension of the loudspeaker. Existing solutions use linear filtering to constrain the amplitude of audio signals to mediate excursions based on a speaker impedance model. This constraint processing may introduce distortion into audio signals or excessively lower the perceived loudness of the audio signal.